225 lines · c
1// SPDX-License-Identifier: GPL-2.02/*3 * Powerpc needs __SANE_USERSPACE_TYPES__ before <linux/types.h> to select4 * 'int-ll64.h' and avoid compile warnings when printing __u64 with %llu.5 */6#define __SANE_USERSPACE_TYPES__7 8#include <stdlib.h>9#include <stdio.h>10#include <unistd.h>11#include <string.h>12#include <sys/ioctl.h>13#include <fcntl.h>14#include <linux/hw_breakpoint.h>15 16#include "tests.h"17#include "debug.h"18#include "event.h"19#include "parse-events.h"20#include "../perf-sys.h"21#include "cloexec.h"22 23/*24 * PowerPC and S390 do not support creation of instruction breakpoints using the25 * perf_event interface.26 *27 * Just disable the test for these architectures until these issues are28 * resolved.29 */30#if defined(__powerpc__) || defined(__s390x__)31#define BP_ACCOUNT_IS_SUPPORTED 032#else33#define BP_ACCOUNT_IS_SUPPORTED 134#endif35 36static volatile long the_var;37 38static noinline int test_function(void)39{40 return 0;41}42 43static int __event(bool is_x, void *addr, struct perf_event_attr *attr)44{45 int fd;46 47 memset(attr, 0, sizeof(struct perf_event_attr));48 attr->type = PERF_TYPE_BREAKPOINT;49 attr->size = sizeof(struct perf_event_attr);50 51 attr->config = 0;52 attr->bp_type = is_x ? HW_BREAKPOINT_X : HW_BREAKPOINT_W;53 attr->bp_addr = (unsigned long) addr;54 attr->bp_len = is_x ? default_breakpoint_len() : sizeof(long);55 56 attr->sample_period = 1;57 attr->sample_type = PERF_SAMPLE_IP;58 59 attr->exclude_kernel = 1;60 attr->exclude_hv = 1;61 62 fd = sys_perf_event_open(attr, -1, 0, -1,63 perf_event_open_cloexec_flag());64 if (fd < 0) {65 pr_debug("failed opening event %llx\n", attr->config);66 return TEST_FAIL;67 }68 69 return fd;70}71 72static int wp_event(void *addr, struct perf_event_attr *attr)73{74 return __event(false, addr, attr);75}76 77static int bp_event(void *addr, struct perf_event_attr *attr)78{79 return __event(true, addr, attr);80}81 82static int bp_accounting(int wp_cnt, int share)83{84 struct perf_event_attr attr, attr_mod, attr_new;85 int i, fd[wp_cnt], fd_wp, ret;86 87 for (i = 0; i < wp_cnt; i++) {88 fd[i] = wp_event((void *)&the_var, &attr);89 TEST_ASSERT_VAL("failed to create wp\n", fd[i] != -1);90 pr_debug("wp %d created\n", i);91 }92 93 attr_mod = attr;94 attr_mod.bp_type = HW_BREAKPOINT_X;95 attr_mod.bp_addr = (unsigned long) test_function;96 attr_mod.bp_len = default_breakpoint_len();97 98 ret = ioctl(fd[0], PERF_EVENT_IOC_MODIFY_ATTRIBUTES, &attr_mod);99 TEST_ASSERT_VAL("failed to modify wp\n", ret == 0);100 101 pr_debug("wp 0 modified to bp\n");102 103 if (!share) {104 fd_wp = wp_event((void *)&the_var, &attr_new);105 TEST_ASSERT_VAL("failed to create max wp\n", fd_wp != -1);106 pr_debug("wp max created\n");107 }108 109 for (i = 0; i < wp_cnt; i++)110 close(fd[i]);111 112 return 0;113}114 115static int detect_cnt(bool is_x)116{117 struct perf_event_attr attr;118 void *addr = is_x ? (void *)test_function : (void *)&the_var;119 int fd[100], cnt = 0, i;120 121 while (1) {122 if (cnt == 100) {123 pr_debug("way too many debug registers, fix the test\n");124 return 0;125 }126 fd[cnt] = __event(is_x, addr, &attr);127 128 if (fd[cnt] < 0)129 break;130 cnt++;131 }132 133 for (i = 0; i < cnt; i++)134 close(fd[i]);135 136 return cnt;137}138 139static int detect_ioctl(void)140{141 struct perf_event_attr attr;142 int fd, ret = 1;143 144 fd = wp_event((void *) &the_var, &attr);145 if (fd > 0) {146 ret = ioctl(fd, PERF_EVENT_IOC_MODIFY_ATTRIBUTES, &attr);147 close(fd);148 }149 150 return ret ? 0 : 1;151}152 153static int detect_share(int wp_cnt, int bp_cnt)154{155 struct perf_event_attr attr;156 int i, *fd = NULL, ret = -1;157 158 if (wp_cnt + bp_cnt == 0)159 return 0;160 161 fd = malloc(sizeof(int) * (wp_cnt + bp_cnt));162 if (!fd)163 return -1;164 165 for (i = 0; i < wp_cnt; i++) {166 fd[i] = wp_event((void *)&the_var, &attr);167 if (fd[i] == -1) {168 pr_err("failed to create wp\n");169 goto out;170 }171 }172 173 for (; i < (bp_cnt + wp_cnt); i++) {174 fd[i] = bp_event((void *)test_function, &attr);175 if (fd[i] == -1)176 break;177 }178 179 ret = i != (bp_cnt + wp_cnt);180 181out:182 while (i--)183 close(fd[i]);184 185 free(fd);186 return ret;187}188 189/*190 * This test does following:191 * - detects the number of watch/break-points,192 * skip test if any is missing193 * - detects PERF_EVENT_IOC_MODIFY_ATTRIBUTES ioctl,194 * skip test if it's missing195 * - detects if watchpoints and breakpoints share196 * same slots197 * - create all possible watchpoints on cpu 0198 * - change one of it to breakpoint199 * - in case wp and bp do not share slots,200 * we create another watchpoint to ensure201 * the slot accounting is correct202 */203static int test__bp_accounting(struct test_suite *test __maybe_unused, int subtest __maybe_unused)204{205 int has_ioctl = detect_ioctl();206 int wp_cnt = detect_cnt(false);207 int bp_cnt = detect_cnt(true);208 int share = detect_share(wp_cnt, bp_cnt);209 210 if (!BP_ACCOUNT_IS_SUPPORTED) {211 pr_debug("Test not supported on this architecture");212 return TEST_SKIP;213 }214 215 pr_debug("watchpoints count %d, breakpoints count %d, has_ioctl %d, share %d\n",216 wp_cnt, bp_cnt, has_ioctl, share);217 218 if (!wp_cnt || !bp_cnt || !has_ioctl)219 return TEST_SKIP;220 221 return bp_accounting(wp_cnt, share);222}223 224DEFINE_SUITE("Breakpoint accounting", bp_accounting);225